How do I know what OS I have?

[mtnman]

How do I know what year my OS is? I see it on the calibration tab of the *.tun file, but there's no indication of a date of the OS.

[Blacky]

Look at page 4 of the Custom OS Tutorial - that lists some of them.
http://www.efilive.com/doc/Tutorials/Custom%20OS%20Upgrade%20Tutorial.pdf

Otherwise send your OS number to GMPX (Ross) and he should be able to tell you.

Regards
Paul